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Electroboom: How Right IS Veritasium?! Don't Electrons Push Each Other??
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m k:

--- Quote from: Nominal Animal on July 20, 2022, 01:17:34 am ---
--- Quote from: Naej on July 19, 2022, 11:32:45 pm ---
--- Quote from: Nominal Animal on July 18, 2022, 10:57:48 am ---
--- Quote from: Naej on July 18, 2022, 08:58:33 am ---What's the difference between "in reality" and "the energy flows in the copper"?
--- End quote ---
In that the properties of the dielectric (insulator) and the geometry of the coaxial cable affect the energy transfer capabilities of the coaxial cable more than the core conductor does.

--- End quote ---
Really? If you replace the core by some plastic, what happens?

--- End quote ---
It becomes a wave guide.  It is only practical at microwave ranges, because in the absence of a conductive core, the dielectric absorbs the energy in the EM field at most frequencies; and the characteristics of the outer "ground" become absolutely crucial, as full reflectance is needed for a viable waveguide.  (We are talking about alternating currents here, after all; since as I already wrote earlier, for direct current, the energy does indeed flow in the conductor.)

More interesting is to examine what happens when you have flaws, say a short break, in the core conductor.  If "the energy flows in the copper", then even a micrometer wide break in the core conductor would stop the energy flow, wouldn't it?  It doesn't (for AC; it would if this was steady-state DC).  It does cause all sorts of reflections and whatnot in AC, but a large fraction of the energy still flows.

This is an excellent example of why it is the geometry and not just the conductor that matters.  It is silly to even attempt to say where the energy flows, unless we exactly specify the geometry of the system we're talking about, since it really does vary from system to system.  The movement of charge carriers, current, is just the easiest way we can exploit the energy flow, make it do useful work; but it isn't exactly how the energy is always transferred within the system.  Sometimes it is, sometimes it isn't: it depends exactly on the geometry/setup of the system.

Naej, I can't tell if you're agreeing with me and just directing the discussion using the Socratic method, asking genuine questions, or whether you have observed a flaw in my reasoning but are unwilling to point it out.  Would you mind telling me?  :)

--- End quote ---

I don't mind you're saying it.

One part is still missing, frequencies where electric energy becomes something else in our spoken language.
Satellite TV receiver is a good example where frequency is too much for copper.

How many times a heat wave must bounce before it becomes a radio wave.
Is it the same wave.
Naej:

--- Quote from: electrodacus on July 20, 2022, 01:22:22 am ---
--- Quote from: Naej on July 20, 2022, 12:43:08 am ---Do you know what Newton's third law is?

--- End quote ---

Yes. Do you know?



--- End quote ---
Yes and if you apply it on F2 what does it say?
Naej:

--- Quote from: Nominal Animal on July 20, 2022, 01:17:34 am ---
--- Quote from: Naej on July 19, 2022, 11:32:45 pm ---
--- Quote from: Nominal Animal on July 18, 2022, 10:57:48 am ---
--- Quote from: Naej on July 18, 2022, 08:58:33 am ---What's the difference between "in reality" and "the energy flows in the copper"?
--- End quote ---
In that the properties of the dielectric (insulator) and the geometry of the coaxial cable affect the energy transfer capabilities of the coaxial cable more than the core conductor does.

--- End quote ---
Really? If you replace the core by some plastic, what happens?

--- End quote ---
It becomes a wave guide.  It is only practical at microwave ranges, because in the absence of a conductive core, the dielectric absorbs the energy in the EM field at most frequencies; and the characteristics of the outer "ground" become absolutely crucial, as full reflectance is needed for a viable waveguide.  (We are talking about alternating currents here, after all; since as I already wrote earlier, for direct current, the energy does indeed flow in the conductor.)

More interesting is to examine what happens when you have flaws, say a short break, in the core conductor.  If "the energy flows in the copper", then even a micrometer wide break in the core conductor would stop the energy flow, wouldn't it?  It doesn't (for AC; it would if this was steady-state DC).  It does cause all sorts of reflections and whatnot in AC, but a large fraction of the energy still flows.

This is an excellent example of why it is the geometry and not just the conductor that matters.  It is silly to even attempt to say where the energy flows, unless we exactly specify the geometry of the system we're talking about, since it really does vary from system to system.  The movement of charge carriers, current, is just the easiest way we can exploit the energy flow, make it do useful work; but it isn't exactly how the energy is always transferred within the system.  Sometimes it is, sometimes it isn't: it depends exactly on the geometry/setup of the system.

Naej, I can't tell if you're agreeing with me and just directing the discussion using the Socratic method, asking genuine questions, or whether you have observed a flaw in my reasoning but are unwilling to point it out.  Would you mind telling me?  :)

--- End quote ---
I want to know why people believe energy is not in conductor and why do they believe this.  :)

The flaw is to think in terms of "reality", because reality doesn't say where energy is or how it flows, as it is a pretty abstract concept. Instead, you choose energy and its flow, and your choice can 100% depend on the frequency/setup/etc.
Nominal Animal:

--- Quote from: Naej on July 20, 2022, 11:11:28 am ---I want to know why people believe energy is not in conductor and why do they believe this.  :)
--- End quote ---
Thank you.

Do note that I do not believe energy flows in the conductor, nor do I believe energy flows outside the conductor.
I believe it depends on the exact geometry of the system, because there are many ways to transfer energy, even when we inject and extract that energy as current flow (movement of charge carriers).

In the case discussed, there are too many small details that can be tweaked just a little bit to change it completely, and that's why nobody seems to agree: they just pick a way, and then describe a system that does so, matching it to the general picture of what is discussed.

It really is like arguing what is the safe maximum speed one can drive a car at, without specifying the road or the driver.  It is useless.


--- Quote from: Naej on July 20, 2022, 11:11:28 am ---The flaw is to think in terms of "reality", because reality doesn't say where energy is or how it flows, as it is a pretty abstract concept.
--- End quote ---
Well, physics does model pretty darn well where energy is and how it flows, even though it has no idea what energy actually is.  To physics and physicists, energy is just a measurable quantity.

Of course, to apply physics, we need to have a precise picture of the exact system involved, because there are so many different ways we know energy can flow.

Just look at exactly how two electrons can interact.  In electrostatics (approximation at very low velocities, so suitable for electrons in a conductor for example), one can use Coulomb's law to obtain the forces between point charges.  This is sufficiently good approximation to model chemistry, for example.   They don't "collide" like marbles do; they interact over distances.  Electrons can also absorb and emit photons, because they are charged particles; and photons are electromagnetic radiation.  So, electrons can also interact via electromagnetic radiation, even when there is no external electromagnetic field present.  Because all matter not at absolute zero temperature emits blackbody radiation, even atoms and electrons deep inside matter are constantly bathed in electromagnetic radiation: thermal radiation.

With direct current, we have a steady state, and not too many wavelike phenomena, and we can say that the energy flow is basically the flow of the charge carriers: the electric current.  With alternating current, we've introduced many new phenomena, many of them wavelike, and in many cases the charge carriers don't move much inside the transmission line as most of the energy flows in the associated electromagnetic field instead.

Discontinuous transitions, like an initial pulse of current or voltage, or even connecting a DC circuit, are the hardest of them all, because it is a non-equilibrium system with all sorts of ancillary energy flows and shockwave-like phenomena and whatnot.  I don't even want to go there in physics; it's too complicated for me to deal with except in the crudest of approximations.
(I do know that the transmission line model can be used very effectively and with reliable results for this, and that's what I'd learn and use if I had to solve a problem like that; but it is more electrical engineering than physics.)
gnuarm:

--- Quote from: electrodacus on July 20, 2022, 06:15:03 am ---
--- Quote from: gnuarm on July 20, 2022, 05:40:51 am ---As soon as you start talking about rubber bands and slipping, you are in the domain of BS.

Fix your car and then try the test again.  Stop with the BS.

--- End quote ---

There is nothing to fix. Any vehicle like this (locked gearbox) will work this way.
If you understood basic high school physics you could understand why that is especially after I spent all this time to explain it to you.

--- End quote ---

Dude, you don't even understand Newton's law which you think you are showing in your image.  You completely fail to understand it does not connect F1 to F2. 

You are a total fail, not worthy of anyone trying to explain it to you. 
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